1. Field of the Invention
The present invention relates to apparatuses for the anaerobic digestion of natural organic waste.
2. Description of the Prior Art
In a known sewage treatment apparatus, sewage for treatment is loaded into a digester in batches at intervals so as to give a hydraulic retention time of from 20 to 40 days. This type of loading can produce a shock load on the microbial population by causing an accumulation of volatile fatty acid which can be toxic to the methane-producing bacteria. It is thought that these long retention times of 20 to 40 days are thus necessary for the bacterial population to acclimatise to the changing environment imposed upon them by this type of feeding mechanism.